1. Field of the Invention
The present invention relates to vehicularly-mountable message boards.
2. Description of the Related Art
When there is an automobile accident, or when construction crews are working on streets and highways, warning signs on the roofs of emergency or construction vehicles are considered a generally accepted method for reducing accidents involving oncoming traffic. Unfortunately, these roof-mounted warning signs, when mounted for maximum visibility, create unwanted wind resistance and clearance hazards for the vehicles when the vehicles are in transit.
In order to minimize the wind resistance caused by these roof-mounted warning signs in addition to preventing damage to the roof of the vehicle from low clearance obstacles, devices have been invented to alternate these roof-mounted warning signs between (1) high-visibility, high wind resistance configurations for when the vehicle is not moving, and (2) low-visibility, low-wind resistance, and generally lower profile configurations for when the vehicle is in transit.
In the past, however, these goals were achieved only through complicated designs that have proven difficult and expensive to manufacture, and which fail to achieve the full potential for maximizing high-profile visibility while maintaining low-profile unobtrusiveness and minimizing manufacturing costs.
For example, U.S. Pat. Nos. 3,761,890, 4,152,854, and 4,259,660 disclose retractable or collapsible warning signs which are mounted to the roof of an automobile. However, these patents do not suggest or teach the benefits that a side-mounted actuating motor with side mounted moment arm can provide in achieving the seemingly diametrically opposed goals of high visibility and a low-profile configuration.
In particular, U.S. Pat. No. 4,152,854 poses clearance problems since it remains notably high above the roof of the vehicle even in the fully retracted configuration. Other devices have utilized a configuration where the motor is located beneath the warning sign when in its retracted position. Devices that utilize an actuator located in the center of the warning sign pose one of two problems. If the actuating motor and moment arm lie underneath the warning sign in the fully retracted configuration, then clearance problems are present since the total clearance of the retraced warning sign must accommodate for the height of the actuating motor and moment arm which are mounted directly beneath the sign.
Other patented devices, such as the sign disclosed in U.S. Pat. No. 4,259,660, sought to alleviate this clearance problem but, unfortunately, created other difficulties in so doing. For example, in the device disclosed in the 4,259,660 patent, the activating motor and the moment arm are on the opposite side of the axis of rotation of the warning sign when the warning sign is in the fully retracted configuration; thus, this automatically retractable warning sign requires a significant and potentially prohibitive length of the vehicle's roof. Moreover, the use of a centrally-located actuation motor and moment arm, as disclosed in the 4,259,660 patent, interferes with the orthogonal visibility of the warning sign.
Still other patented devices, such as the device disclosed in U.S. Pat. No. 3,761,890, created the disadvantages associated with complex drive mechanisms. In particular, the 3,761,890 patent discloses a device which utilizes a complex dual-drive mechanism with two moment arms to rotate an apparatus from a display position to a retracted position. Such complexity is particularly disadvantageous in view of the difficulty and expense associated with manufacturing such a system.